Emergent behavior in a coupled economic and coastline model for beach nourishment

Journal Article (Journal Article)

Developed coastal areas often exhibit a strong systemic coupling between shoreline dynamics and economic dynamics. "Beach nourishment", a common erosion-control practice, involves mechanically depositing sediment from outside the local littoral system onto an actively eroding shoreline to alter shoreline morphology. Natural sedimenttransport processes quickly rework the newly engineered beach, causing further changes to the shoreline that in turn affect subsequent beach-nourishment decisions. To the limited extent that this landscape/economic coupling has been considered, evidence suggests that towns tend to employ spatially myopic economic strategies under which individual towns make isolated decisions that do not account for their neighbors. What happens when an optimization strategy that explicitly ignores spatial interactions is incorporated into a physical model that is spatially dynamic? The longterm attractor that develops for the coupled system (the state and behavior to which the system evolves over time) is unclear. We link an economic model, in which town-manager agents choose economically optimal beach-nourishment intervals according to past observations of their immediate shoreline, to a simplified coastal-dynamics model that includes alongshore sediment transport and background erosion (e.g. from sea-level rise). Simulations suggest that feedbacks between these human and natural coastal processes can generate emergent behaviors. When alongshore sediment transport and spatially myopic nourishment decisions are coupled, increases in the rate of sea-level rise can destabilize economically optimal nourishment practices into a regime characterized by the emergence of chaotic shoreline evolution. © Author(s) 2011.

Full Text

Duke Authors

Cited Authors

  • Lazarus, ED; McNamara, DE; Smith, MD; Gopalakrishnan, S; Murray, AB

Published Date

  • December 1, 2011

Published In

Volume / Issue

  • 18 / 6

Start / End Page

  • 989 - 999

Electronic International Standard Serial Number (EISSN)

  • 1607-7946

International Standard Serial Number (ISSN)

  • 1023-5809

Digital Object Identifier (DOI)

  • 10.5194/npg-18-989-2011

Citation Source

  • Scopus